func (this *varintWriter) WriteMsg(msg proto.Message) (err error) {
	var data []byte
	if m, ok := msg.(marshaler); ok {
		n := m.Size()
		if n >= len(this.buffer) {
			this.buffer = make([]byte, n)
		}
		_, err = m.MarshalTo(this.buffer)
		if err != nil {
			return err
		}
		data = this.buffer[:n]
	} else {
		data, err = proto.Marshal(msg)
		if err != nil {
			return err
		}
	}
	length := uint64(len(data))
	n := binary.PutUvarint(this.lenBuf, length)
	_, err = this.w.Write(this.lenBuf[:n])
	if err != nil {
		return err
	}
	_, err = this.w.Write(data)
	return err
}

func TestGetExtensionStability(t *testing.T) {
	check := func(m *pb.MyMessage) bool {
		ext1, err := proto.GetExtension(m, pb.E_Ext_More)
		if err != nil {
			t.Fatalf("GetExtension() failed: %s", err)
		}
		ext2, err := proto.GetExtension(m, pb.E_Ext_More)
		if err != nil {
			t.Fatalf("GetExtension() failed: %s", err)
		}
		return ext1 == ext2
	}
	msg := &pb.MyMessage{Count: proto.Int32(4)}
	ext0 := &pb.Ext{}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext0); err != nil {
		t.Fatalf("Could not set ext1: %s", ext0)
	}
	if !check(msg) {
		t.Errorf("GetExtension() not stable before marshaling")
	}
	bb, err := proto.Marshal(msg)
	if err != nil {
		t.Fatalf("Marshal() failed: %s", err)
	}
	msg1 := &pb.MyMessage{}
	err = proto.Unmarshal(bb, msg1)
	if err != nil {
		t.Fatalf("Unmarshal() failed: %s", err)
	}
	if !check(msg1) {
		t.Errorf("GetExtension() not stable after unmarshaling")
	}
}

func (n *FSNode) GetBytes() ([]byte, error) {
	pbn := new(pb.Data)
	pbn.Type = &n.Type
	pbn.Filesize = proto.Uint64(uint64(len(n.Data)) + n.subtotal)
	pbn.Blocksizes = n.blocksizes
	pbn.Data = n.Data
	return proto.Marshal(pbn)
}

// putLocal stores the key value pair in the datastore
func (dht *IpfsDHT) putLocal(key key.Key, rec *pb.Record) error {
	data, err := proto.Marshal(rec)
	if err != nil {
		return err
	}

	return dht.datastore.Put(key.DsKey(), data)
}

func (sk *RsaPrivateKey) Bytes() ([]byte, error) {
	b := x509.MarshalPKCS1PrivateKey(sk.sk)
	pbmes := new(pb.PrivateKey)
	typ := pb.KeyType_RSA
	pbmes.Type = &typ
	pbmes.Data = b
	return proto.Marshal(pbmes)
}

// MarshalPrivateKey converts a key object into its protobuf serialized form.
func MarshalPrivateKey(k PrivKey) ([]byte, error) {
	b := MarshalRsaPrivateKey(k.(*RsaPrivateKey))
	pmes := new(pb.PrivateKey)
	typ := pb.KeyType_RSA // for now only type.
	pmes.Type = &typ
	pmes.Data = b
	return proto.Marshal(pmes)
}

func newTestMessage() *pb.MyMessage {
	msg := &pb.MyMessage{
		Count: proto.Int32(42),
		Name:  proto.String("Dave"),
		Quote: proto.String(`"I didn't want to go."`),
		Pet:   []string{"bunny", "kitty", "horsey"},
		Inner: &pb.InnerMessage{
			Host:      proto.String("footrest.syd"),
			Port:      proto.Int32(7001),
			Connected: proto.Bool(true),
		},
		Others: []*pb.OtherMessage{
			{
				Key:   proto.Int64(0xdeadbeef),
				Value: []byte{1, 65, 7, 12},
			},
			{
				Weight: proto.Float32(6.022),
				Inner: &pb.InnerMessage{
					Host: proto.String("lesha.mtv"),
					Port: proto.Int32(8002),
				},
			},
		},
		Bikeshed: pb.MyMessage_BLUE.Enum(),
		Somegroup: &pb.MyMessage_SomeGroup{
			GroupField: proto.Int32(8),
		},
		// One normally wouldn't do this.
		// This is an undeclared tag 13, as a varint (wire type 0) with value 4.
		XXX_unrecognized: []byte{13<<3 | 0, 4},
	}
	ext := &pb.Ext{
		Data: proto.String("Big gobs for big rats"),
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext); err != nil {
		panic(err)
	}
	greetings := []string{"adg", "easy", "cow"}
	if err := proto.SetExtension(msg, pb.E_Greeting, greetings); err != nil {
		panic(err)
	}

	// Add an unknown extension. We marshal a pb.Ext, and fake the ID.
	b, err := proto.Marshal(&pb.Ext{Data: proto.String("3G skiing")})
	if err != nil {
		panic(err)
	}
	b = append(proto.EncodeVarint(201<<3|proto.WireBytes), b...)
	proto.SetRawExtension(msg, 201, b)

	// Extensions can be plain fields, too, so let's test that.
	b = append(proto.EncodeVarint(202<<3|proto.WireVarint), 19)
	proto.SetRawExtension(msg, 202, b)

	return msg
}

// MarshalPublicKey converts a public key object into a protobuf serialized
// public key
func MarshalPublicKey(k PubKey) ([]byte, error) {
	b, err := MarshalRsaPublicKey(k.(*RsaPublicKey))
	if err != nil {
		return nil, err
	}
	pmes := new(pb.PublicKey)
	typ := pb.KeyType_RSA // for now only type.
	pmes.Type = &typ
	pmes.Data = b
	return proto.Marshal(pmes)
}

func (c *offlineRouting) PutValue(ctx context.Context, key key.Key, val []byte) error {
	rec, err := record.MakePutRecord(c.sk, key, val, false)
	if err != nil {
		return err
	}
	data, err := proto.Marshal(rec)
	if err != nil {
		return err
	}

	return c.datastore.Put(key.DsKey(), data)
}

// Returns Bytes that represent a Directory
func FolderPBData() []byte {
	pbfile := new(pb.Data)
	typ := pb.Data_Directory
	pbfile.Type = &typ

	data, err := proto.Marshal(pbfile)
	if err != nil {
		//this really shouldnt happen, i promise
		panic(err)
	}
	return data
}

func putRoutingRecord(ds datastore.Datastore, k key.Key, value *dhtpb.Record) error {
	data, err := proto.Marshal(value)
	if err != nil {
		return err
	}
	dskey := k.DsKey()
	// TODO namespace
	if err := ds.Put(dskey, data); err != nil {
		return err
	}
	return nil
}

func SymlinkData(path string) ([]byte, error) {
	pbdata := new(pb.Data)
	typ := pb.Data_Symlink
	pbdata.Data = []byte(path)
	pbdata.Type = &typ

	out, err := proto.Marshal(pbdata)
	if err != nil {
		return nil, err
	}

	return out, nil
}

func BytesForMetadata(m *Metadata) ([]byte, error) {
	pbd := new(pb.Data)
	pbd.Filesize = proto.Uint64(m.Size)
	typ := pb.Data_Metadata
	pbd.Type = &typ
	mdd, err := m.Bytes()
	if err != nil {
		return nil, err
	}

	pbd.Data = mdd
	return proto.Marshal(pbd)
}

func WrapData(b []byte) []byte {
	pbdata := new(pb.Data)
	typ := pb.Data_Raw
	pbdata.Data = b
	pbdata.Type = &typ

	out, err := proto.Marshal(pbdata)
	if err != nil {
		// This shouldnt happen. seriously.
		panic(err)
	}

	return out
}

func createRoutingEntryData(pk ci.PrivKey, val path.Path) ([]byte, error) {
	entry := new(pb.IpnsEntry)

	entry.Value = []byte(val)
	typ := pb.IpnsEntry_EOL
	entry.ValidityType = &typ
	entry.Validity = []byte(u.FormatRFC3339(time.Now().Add(time.Hour * 24)))

	sig, err := pk.Sign(ipnsEntryDataForSig(entry))
	if err != nil {
		return nil, err
	}
	entry.Signature = sig
	return proto.Marshal(entry)
}

func TestPBNodeVerboseEqual(t *testing.T) {
	popr := math_rand.New(math_rand.NewSource(time.Now().UnixNano()))
	p := NewPopulatedPBNode(popr, false)
	data, err := github_com_gogo_protobuf_proto.Marshal(p)
	if err != nil {
		panic(err)
	}
	msg := &PBNode{}
	if err := github_com_gogo_protobuf_proto.Unmarshal(data, msg); err != nil {
		panic(err)
	}
	if err := p.VerboseEqual(msg); err != nil {
		t.Fatalf("%#v !VerboseEqual %#v, since %v", msg, p, err)
	}
}

func BenchmarkPBLinkProtoMarshal(b *testing.B) {
	popr := math_rand.New(math_rand.NewSource(616))
	total := 0
	pops := make([]*PBLink, 10000)
	for i := 0; i < 10000; i++ {
		pops[i] = NewPopulatedPBLink(popr, false)
	}
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		data, err := github_com_gogo_protobuf_proto.Marshal(pops[i%10000])
		if err != nil {
			panic(err)
		}
		total += len(data)
	}
	b.SetBytes(int64(total / b.N))
}

// Store a value in this peer local storage
func (dht *IpfsDHT) handlePutValue(ctx context.Context, p peer.ID, pmes *pb.Message) (*pb.Message, error) {
	defer log.EventBegin(ctx, "handlePutValue", p).Done()
	dskey := key.Key(pmes.GetKey()).DsKey()

	if err := dht.verifyRecordLocally(pmes.GetRecord()); err != nil {
		log.Debugf("Bad dht record in PUT from: %s. %s", key.Key(pmes.GetRecord().GetAuthor()), err)
		return nil, err
	}

	data, err := proto.Marshal(pmes.GetRecord())
	if err != nil {
		return nil, err
	}

	err = dht.datastore.Put(dskey, data)
	log.Debugf("%s handlePutValue %v", dht.self, dskey)
	return pmes, err
}

func FilePBData(data []byte, totalsize uint64) []byte {
	pbfile := new(pb.Data)
	typ := pb.Data_File
	pbfile.Type = &typ
	pbfile.Data = data
	pbfile.Filesize = proto.Uint64(totalsize)

	data, err := proto.Marshal(pbfile)
	if err != nil {
		// This really shouldnt happen, i promise
		// The only failure case for marshal is if required fields
		// are not filled out, and they all are. If the proto object
		// gets changed and nobody updates this function, the code
		// should panic due to programmer error
		panic(err)
	}
	return data
}

func TestPBNodeSize(t *testing.T) {
	popr := math_rand.New(math_rand.NewSource(time.Now().UnixNano()))
	p := NewPopulatedPBNode(popr, true)
	size2 := github_com_gogo_protobuf_proto.Size(p)
	data, err := github_com_gogo_protobuf_proto.Marshal(p)
	if err != nil {
		panic(err)
	}
	size := p.Size()
	if len(data) != size {
		t.Fatalf("size %v != marshalled size %v", size, len(data))
	}
	if size2 != size {
		t.Fatalf("size %v != before marshal proto.Size %v", size, size2)
	}
	size3 := github_com_gogo_protobuf_proto.Size(p)
	if size3 != size {
		t.Fatalf("size %v != after marshal proto.Size %v", size, size3)
	}
}